Unmatched bets were not voided after a red card

[alex33]

Today I tried to trade a low-liquidity match. There was no movement on the market, and I couldn't sell anything. Suddenly, a red card occurred, and unmatched bets weren't voided after a live red card and were matched. I'm absolutely certain of this because the bet was up for about 10-15minutes without being matched. It was only a few seconds after I switched tabs that I returned to see that the bet had been fully matched.
I'm sure this is a scam, someone took advantage of the fact that the market was forgotten to suspended in time, but I can't prove it. Is there any way to verify this other than taking Betfair's word for it?